Plasma Concentrations of Fe, Cu, Mn, and Cr of Maternal and Umbilical Cord Blood during Pregnancy

Anemia is prevalent among pregnant women in Korea, and Fe deficiency anemia is a major nutritional problem throughout the world. Because studies of Cu, Mn, and Cr levels excluding Fe are rare, we were interested in changes in the nutritional status of these trace minerals and their relationship to hematogenesis. Accordingly, we determined the changes in plasma Fe, Cu, Mn, and Cr concentrations of maternal and umbilical cord blood during pregnancy, and evaluated the relationships between them at different time points during pregnancy. A total of 81 women participated in the study: 26 subjects in the first trimester, 23 in the second, and 32 in the third trimester. Plasma Fe levels were lower significantly (p<0.05) in the third trimester. Plasma Cu level ($\mu\textrm{g}$/dL) in each trimester were 86.6$\pm$13.8, 111.6$\pm$27.9, and 114.0$\pm$29.7, respectively; with significant increases (p<0.()5) in the second and third trimester. Plasma Mn concentrations (pg/dL) in each trimester were 212.6$\pm$89.0, 234.0$\pm$140.0, and 240.3$\pm$166.0, respectively and tended to increase, though not significantly, as the pregnancies progressed. The plasma concentrations of Cr (pg/dL) in each trimester were 3.7$\pm$2.0, 3.1$\pm$1.0, and 2.4$\pm$1.2, respectively; and was significantly lower (p<0.05) in the third trimester. In umbilical cord blood, the plasma level of Fe was 194.8$\pm$74.6 $\mu\textrm{g}$/dL, Cu was 57.5$\pm$10.9 $\mu\textrm{g}$/dL, Mn was 482.4$\pm$111.1 pg/dL, and Cr was 9.3$\pm$2.8 pg/dL. Plasma concentrations of Fe, Cu, Mn, and Cr of cord blood were 300 %, 50 %, 200 %, and 370% as compared to those of maternal blood in the third trimester. These results suggest that an active transport mechanism for the transport of Fe, Mn, and Cr from mother to fetus may exist, whereas, for Cu, the placenta appears to have a blocking effect on the transport from mother to baby.